Expandable trailers are often used as house trailers where it is useful be able to collapse a trailer into a more easily transportable form. Quite often, in order to have a structurally stable expandable portion of the trailer, the trailer interior must receive the expandable portion when in the collapsed or retracted position. This can be quite inconvenient as the expandable portion may obstruct the trailer interior and make it difficult to position furniture and the like. Examples of such trailers are disclosed in U.S. Pat. No. 5,280,985 (Morris) and U.S. Pat. No. 5,237,782 (Cooper).
This problem has been addressed in part by U.S. Pat. No. 2,901,282 (Meaker) which discloses a telescopically collapsible house trailer in which the trailer interior is left completely unobstructed. The expandable portion comprises foldable floor elements which are folded up into parallel retracted position at one side of the trailer when it is being transported. When the trailer is expanded, these floor elements fold out to form the expanded portion. Although the trailer interior is not obstructed by the expandable portion, this trailer construction does have a number of drawbacks. The expandable portion cannot support any furniture or the like during transport as the floor elements must be folded up into the retracted position. In addition, as only one side of the trailer supports the expandable portion, balance may also be a concern when the trailer is expanded, particularly when containing heavy loads.
Thus, there exists a need for an expandable trailer with increased stability and improved supports so that the expanded portion of the trailer remains level. Preferably, such an expandable trailer would be able to store furniture and the like in the expandable portion when the trailer is in a retracted position.